Why does the title say "Every pony sings rotten family". even though you didn't include Bonbon and Lyra, what let me just *checking if he/she forgot Lyra and bonbon by reawatching the vid *, yep, you forgot them
Idk but spike really dose fit in place of Stewie seeing his is a small kid like character who is lost and sees the most important people in his life get corrupted and he has no way to save them
sorry for many comments But rarity loses all of them she loses applejack twilight fluttershy pinkie rainbow dash but atleast she did not lose his sister and Other Sad:(
I know there's no actually "everypony" but song is too short to put them all like, if characters changed every turn then there's would be even less characters in cover. And those too random guy are characters that are part of the fandom.